From 8c36fdf5ed48cc17a257e71e168883307ce89b0e Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Wed, 19 Jul 2017 21:30:42 -0500 Subject: [PATCH] signal: Reduce copy_siginfo to just a memcpy The savings for copying just part of struct siginfo appears to be in the noise on modern machines. So remove this ``optimization'' and simplify the code. At the same time mark the second parameter as constant so there is no confusion as to which direction the copy will go. This ensures that a fully initialized siginfo that is sent ends up as a fully initialized siginfo on the signal queue. This full initialization ensures even confused code won't copy unitialized data to userspace, and it prepares for turning copy_siginfo_to_user into a simple copy_to_user. Signed-off-by: "Eric W. Biederman" --- include/linux/signal.h | 8 ++------ 1 file changed, 2 insertions(+), 6 deletions(-) diff --git a/include/linux/signal.h b/include/linux/signal.h index 042968dd98f0..8037b503ce91 100644 --- a/include/linux/signal.h +++ b/include/linux/signal.h @@ -11,13 +11,9 @@ struct task_struct; /* for sysctl */ extern int print_fatal_signals; -static inline void copy_siginfo(struct siginfo *to, struct siginfo *from) +static inline void copy_siginfo(struct siginfo *to, const struct siginfo *from) { - if (from->si_code < 0) - memcpy(to, from, sizeof(*to)); - else - /* _sigchld is currently the largest know union member */ - memcpy(to, from, __ARCH_SI_PREAMBLE_SIZE + sizeof(from->_sifields._sigchld)); + memcpy(to, from, sizeof(*to)); } int copy_siginfo_to_user(struct siginfo __user *to, const struct siginfo *from);